Organosilicon diamine antimicrobial compound

ABSTRACT

Organosilicon diamine antimicrobial compounds are described, particularly, ammonium chloride derivatives of multifunctional diamino quanternary salts, and salts containing a combination of amino, ester, and fluoroalkyl, functionality.

This is a division of co-pending application Ser. No. 182,698, filed onApr. 18, 1988, now U.S. Pat. No. 4,866,192.

BACKGROUND OF THE INVENTION

This invention relates to antimicrobial agents and more particularly tonew diamine salt compounds having biological activity.

Antimicrobial agents are chemical compositions that are used to preventmicrobiological contamination and deterioration of products, materials,and systems. Particular areas of application of antimicrobial agents andcompositions are, for example, cosmetics, disinfectants, sanitizers,wood preservation, food, animal feed, cooling water, metalworkingfluids, hospital and medical uses, plastics and resins, petroleum, pulpand paper, textiles, latex, adhesives, leather and hides, and paintslurries. Of the diverse categories of antimicrobial agents andcompositions, quaternary ammonium compounds represent one of the largestof the classes of antimicrobial agents in use. At low concentrations,quaternary ammonium type antimicrobial agents are bacteriostatic,fungistatic, algistatic, sporostatic, and tuberculostatic. At mediumconcentrations they are bactericidal, fungicidal, algicidal, andviricidal against lipophilic viruses. Silicone quaternary ammonium saltcompounds are well known as exemplified by U.S. Pat. No. 3,560,385,issued Feb. 2, 1971, and the use of such compounds as antimicrobialagents is taught, for example, in a wide variety of patents such as U.S.Pat. Nos. 3,730,701, issued May 1, 1973, and 3,817,739, issued Jun. 18,1974, where the compounds are used to inhibit algae; 3,794,736, issuedFeb. 26, 1974, and 3,860,709, issued Jan. 14, 1975, where they areemployed for sterilizing or disinfecting a variety of surfaces andinstruments; 3,865,728, issued Feb. 11, 1975,where the compounds areused to treat aquarium filters; 4,259,103, issued Mar. 31, 1981; and inBritish Pat. No. 1,386,876, of Mar. 12, 1975. Published unexaminedEuropean application No. 228464 of Jul. 15, 1987, teaches thatmicroorganisms on plants can be killed by the application thereto of anaqueous mixture of a surfactant and an organosilicon quaternary ammoniumcompound. In a particular application of an antimicrobial siliconequaternary ammonium compound, a paper substrate is rendered resistant tothe growth of microorganisms in U.S. Pat. No. 4,282,366, issued Aug. 4,1981. In U.S. Pat. No. 4,504,541, issued Mar. 12, 1985, an antimicrobialfabric is disclosed which is resistant to discoloration and yellowing bytreatment of the fabric with a quaternary ammonium base containing anorganosilicone. U.S. Pat. No. 4,615,937, issued Oct. 7, 1986, as well asits companion U.S. Pat. No. 4,692,374, issued Sept. 8, 1987, relate towet wiper towelettes having an antimicrobial agent substantive to thefibers of the web and being an organosilicon quaternary ammoniumcompound. In a series of Burlington Industries, Inc. U.S. Pat. Nos.4,408,996, issued Oct. 11, 1983, 4,414,268, issued Nov. 8, 1983,4,425,372, issued Jan. 10, 1984, and 4,395,454, issued Jul. 26, 1983,such compounds are disclosed to be useful in surgical drapes, dressings,and bandages. This same assignee also discloses these compounds as beingemployed in surgeon's gowns in U.S. Pat. Nos. 4,411,928, issued Oct. 25,1983, and 4,467,013, issued Aug. 21, 1984. Organosilicon quaternaryammonium compounds have been employed in carpets, in U.S. Pat. No.4,371,577, issued Feb. 1, 1983; applied to walls, added to paints, andsprayed into shoes, in U.S. Pat. No. 4,394,378, issued Jul. 19, 1983;applied to polyethylene surfaces and used in pillow ticking in U.S. Pat.No. 4,721,511, issued Jan. 26, 1988; in flexible polyurethane foams offine-celled, soft, resilient articles of manufacture in U.S. Pat. No.4,631,297, issued Dec. 23, 1986; and mixed with a surfactant in JapaneseKokai application No. 58-156809, filed Aug. 26, 1983, of Sanyo ChemicalIndustries, Ltd., for the purpose of achieving uniformity ofdistribution of the compounds to a surface. Thus, the versatility ofsuch compositions is readily apparent. However, no one, as far as isknown, has disclosed an organosilicon quaternary ammonium compound ofthe group of new compounds in accordance with the present invention andhaving utility as antimicrobially effective agents. The group of newcompositions of the present invention act in preventing microbiologicalcontamination and deterioration, and the new and heretofore undisclosedgroup of novel compositions set forth in the present invention possesunique features and advantages over existing antimicrobial treatingagents and provide improved results thereover. Thus, the existingdisadvantages of the prior art compounds are overcome with the presentinvention wherein improved and new antimicrobial agents are provided.

SUMMARY OF THE INVENTION

This invention relates to a group of new compounds represented by one ofthe following formulas: ##STR1## wherein A and B are each independentlyselected from methyl, ethyl, and propyl radicals;

R' is selected from methyl, ethyl, propyl, iso-propyl, and butylradicals;

R" is selected from benzyl, CF₃ (CF₂).sub.× --, CH₁₈ H₃₇, CF₃(CH₂).sub.× --, --(CH₂).sub.×SiR'_(u) (OR')_(v) R, alkyl, alkenyl, aryl,and arylalkyl radicals;

R'" is CH₂ --G wherein

G is selected from R', R", ethers, ketones, esters, or CO₂ R groups;

u has a value of from 0 to 2;

v has a value of from 0 to 2 with the proviso that u+v cannot exceed 2;

x has a value of from 0 to 18;

y has a value of 2;

z has a value of from 2 to 18; and

R is selected from R', R", or R'".

Representative of such category of new compounds and to which the hereindisclosed invention relates can be named, for example:

dimethyl-2-(dimethylamino)ethyl-3-(trimethoxysilyl)propylammoniumchloride,

N,N-Dimethyl-N-(methoxycarbonyl)methyl-N',N'-dimethyl-N'-{3-(trimethoxysilyl)propyl}ethylenediammonium dichloride,

N-Benzyl-N,N-dimethyl-N',N'-dimethyl-N'-{3-(trimethoxysilyl)propyl}ethylenediammonium dichloride,

3-{N-2(methoxycarbonylethyl)-N-3-(trimethoxysilyl)propyl}aminopropyldimethyl-(ethoxycarbonylmethyl)ammoniumchloride,

3-{N-2-(methoxycarbonylethyl)-N-{3-(trimethoxysilyl)propyl}aminopropylbenzyldimethyl-ammoniumchloride,

N,N,N-benzyldimethyl-N',N',N-benzyl-2-(methoxycarbonylethyl)-3-(trimethoxysilylpropyl)propylene-1,3-diammoniumdichloride,

3-{N-2-(Methoxycarbonylethyl)-N-3-(trimethoxysilylpropyl)}aminopropyldimethyl-5-(isopropoxycarbonylpentyl)ammoniumchloride,

3-{N-2-(Methoxycarbonylethyl)-N-3-(trimethoxysilylpropyl)}aminopropyldimethylpentylammoniumchloride,

3-{N-{3-(Methoxymethyl-3,3,3-trifluoropropylsilylpropoxycarbonylethyl)}-N-{3-(trimethoxysilylpropyl)}}aminopropyldimethyl-5-(isopropoxycarbinylpentyl)ammoniumchloride,

3-{N-{3-(Methoxymethyl-3,3,3-trifluoropropylsilypropoxycarbonylethyl)}-N-{3-(trimethoxysilylpropyl)}}aminopropyldimethyl-pentylammoniumchloride, and

3-{N-{3-(Methoxymethyl-3,3,3-trifluoropropylsilylpropoxycarbonylethyl)}-N-{3-(trimethoxysilylpropyl)}}-N',N'-dimethyl-amine-1,3.

Hereinafter and in the interest of simplicity, the foregoing quaternaryammonium compounds 1-10 will be referred to as Quats 1-10, respectively,and the formulas for such compounds are set forth hereinbelow andcorrespond to Quats 1-10 named above. Compound No. 11 is an intermediatefor Quat Nos. 9 and 10. As noted hereinbefore, such novel compounds haveutility as antimicrobially active agents. ##STR2## wherein Me is methyland Ph is phenyl.

It is therefore an object of the present invention to provide a newseries of quaternary ammonium salt compounds having biological activity.

These and other objects, features, and advantages of the herein definedinvention will become readily apparent from the following detaileddescription of the present invention.

DETAILED DESCRIPTION

This invention relates to quaternary ammonium salt compounds possessingbiological activity, and including di-quaternary amine salts andmono-quaternary amine salts as fifty percent solids in MeOH. These saltsinclude combinations of ester, fluorocarbon, benzyl, amino, and alkyl,functionality. Di-quaternary ammonium salts of the general structuregiven in equation 1 were prepared. ##STR3##

Mono-quaternary ammonium salts of the general structure shown inequation 2 were also prepared. ##STR4##

The preparation of the equation (1) compounds was initiated by refluxingin methanol two equivalents of 3-(trimethoxysilyl)propyl chloride,(hereinafter referred to as TMSPC), and one equivalent of N, N, N',N'-tetramethylethylenediamine to provide di-quaternary derivatives. Thereaction resulted in Quat 1. ##STR5##

The preparation of Quats 2-3 was carried out by refluxing Quat 1 inmethanol with chloromethyl acetate and benzyl chloride as shown inequation 1 where R=CH2CO2Me and CH2Ph, respectively. Amine "13" as aprecursor was prepared as shown in equation 4. ##STR6##

A GC mass spectral (GCMS) analysis showed a first product peak to beAmine "13" and the second product peak to be a "bis-body" Amine "14" ofequation 8. ##STR7##

Amine "13" was reacted with methyl chloroacetate as outlined in equation9. ##STR8##

A method of converting the secondary amino site to an amino site byMichael addition of the secondary amine to methyl acrylate wasconducted, and the Michael addition of Amine "13" to methyl acrylateresulted in diamine 15 as seen in equation 10. ##STR9##

Five quat salt derivatives of diamine 15 were prepared. The derivativeof methyl chloroacetate was prepared by mixing the amine and methylchloroacetate, providing Quat 4 as a viscous syrup. Benzyl Quat 5 wasprepared in a similar fashion from benzyl chloride. The benzylquaternary salt was again prepared using a larger excess of benzylchloride which resulted in more starting amine relative to benzylchloride at the end of the reaction.

The reaction was continued by adding excess benzyl chloride to formdi-quaternary ammonium Quat 6. A derivative of the diamine 15 andiso-propyl-6-chlorohexanoate was prepared in the manner noted above. Thereaction provided Quat 7. Quat 8 was also prepared using n-pentylchloride. Fluorine-containing derivatives of Amine "13" were alsoprepared. Allyl acrylate was reacted with3-(3,3,3-trifluoro)propylmethoxymethylsilane using an activated platinummetal catalyst providing acrylate 16 shown in equation 11. Thechlorosilane was treated with methanol containing an equivalent oftriethyl amine resulting in methoxysilane 17. ##STR10##

Starting amine and acrylate ester resulted in Michael adduct 11.##STR11##

The material was stripped of all volatile components and divided to makequaternary derivatives of iso-propyl-6-chlorohexanoate and n-pentylchloride corresponding to Quat 9 and Quat 10, respectively.

The foregoing brief reaction sequence when taken in conjunction with thefollowing detailed Examples, show that di-quaternary amines may beprepared by the reaction of 3-chloropropyltrimethoxysilane withtetramethylethylenediamine followed by methanol reflux with anappropriate halo compound. The foregoing also showsN,N-dimethyl-N'-{3-(trimethylsilyl)propyl}ethylenediamine to be a viableprecursor to quaternary amines of varied functionality. Michael additionof amine hydrogen to acrylates is shown to be an effective method ofincorporating diverse functionality. All of the quaternary salts andprecursors were analyzed by nuclear magnetic resonance (NMR)spectroscopy and by IR spectroscopy and were consistent with theassigned structures.

EXAMPLE I A. Synthesis of Quat 1

A stirred solution of 100 gm (0.504 mol) of TMSPC, 31.5 gm (0.272 mol)of tetramethylethylenediamine, and 64 gm of MeOH was charged to a 500 mlround bottom flask and heated to reflux. The reaction was monitored byGC which showed a decrease in starting materials up to 44 hours. Afterthis time, the reaction was cooled to room temperature and excessreagents removed by rotary evaporation at 50° C. and 0.2 mm Hg. Theresulting crystals of Quat 1 were added to 500 ml portions of ether andwashed to remove contaminates.

EXAMPLE II B. Synthesis of Quat 2

A solution of 50 gm (0.158 mol) of Quat 1, 18.5 gm (0.17 mol) of methylchloroacetate, and 30 gm of MeOH was charged to a 500 ml round bottomflask and heated to reflux with stirring. Reflux temperature was 71° C.The reaction was monitored by GC and after 21 hours no more decrease inthe methyl chloroacetate occurred. A Dean-Stark take off tube wasarranged and about 15 gm of methanol removed. The reflux temperature wasincreased to 77° C. for 3 hours. GC did not show additional decrease inthe methyl chloroacetate but the reflux was continued for 4.5 hourslonger and cooled to room temperature. The resulting compound was Quat2.

EXAMPLE III C. Synthesis of Quat 3

A solution of 50 gm (0.16 mol) of Quat 1, 40.6 gm (0.32 mol) of benzylchloride, and 20 gm of MeOH was charged to a 500 ml round bottom flaskand heated to reflux with stirring. The reaction was monitored by GCuntil about 50% of the benzyl chloride was consumed. GC showed theappearance of another peak identified by GCMS as benzyl methyl ether.The crude product was stripped of excess reagents by rotary evaporationyielding a pale yellow crystalline product. The crystals of Quat 3 werewashed repeatedly with tetrahydrofuran (THF) and methanol to removecontaminates and the solvent was removed by rotary evaporation.

EXAMPLE IV D. Synthesis ofN,N-dimethyl-N'-(3-trimethoxysilylpropyl)propylenediamine-1,3 FromN,N-Dimethylpropylenediamine and 3-Chloropropyltrimethoxysilane(TMSPC)

A stirred solution of 200 gm (1.01 mol) of TMSPC, 110 gm (1.08M) ofN,N-dimethylpropylenediamine, and 45 gm of MeOH was heated to reflux ina 1 liter flask and monitored by GC. After stirring overnight (ca. 28hours), GC showed TMSPC was consumed affording a yellow viscous liquid.A small scale neutralization was carried out in a vial by shaking 5.5 gmof crude product with 0.9 gm of NaOMe in 6 ml of MeOH. GC and GC massspectral (GCMS) analysis showedN,N-dimethyl-N'-(3-trimethoxysilylpropyl)proplyenediamine-1,3 andN,N-bis(3-trimethoxysilylpropyl)-N',N'-dimethylpropylenediamine-1,3 in a5:1 ratio. The remainder of the crude product was neutralized with 74 gmof NaOMe in 150 ml of MeOH for 0.5 hours at room temperature. Themixture was allowed to settle and the supernatant decanted for salts.Volatile components were removed by rotary evaporation leaving 188.4 gmof crude product which was flash bulb-to-bulb distilled between117°-139° C./4 mm Hg and collected at -78° C. resulting in 93.2 gm (ca.47% crude yield). The distillate was subjected to rotary evaporation at80° C./0.5 mm Hg to remove the remaining volatile components resultingin 50.1 gm of 84.4% GC areaN,N-dimethyl-N'-(3-trimethoxyproply)proplyenediamine (25.3% yield).

EXAMPLE IV-A

A solution of 218.4 gm (1.1 mol) of TMSPC, 277.0 gm (2.72 mol) ofN,N-dimethylpropylenediamine, and 60.0 gm of MeOH were placed in a roundbottom flask with a drying tube at ambient (27° C.) temperature. Withstirring, the temperature spontaneously increased to 36° C. over 5minutes and then began to cool. The stirred solution was heated to 99°C. GC analysis showed that the starting reagents were reacting to a newproduct. After 2.5 hours and at a temperature maximum of 103° C., GCshowed no further change in the mixture. After cooling to 37° C., aslurry of 60.0 gm of NaOMe in 150 ml of MeOH was added to neutralize theamine hydrochloride. The temperature spontaneously increased to 47° C.and the mixture was stirred for 45 minutes and cooled to roomtemperature. Excess volatile components were removed by rotaryevaporation resulting in 185.5 gm of residue which showed 91.6%N,N-dimethyl-N'-(3 -trimethoxypropyl)propylenediamine and 5.2%N,N-bis(3-trimethoxypropyl)-N',N' -dimethylpropylenediamine by GC. Whenthe final product was allowed to stand at room temperature, a two phasemixture resulted. The top phase wasN,N-dimethyl-N'-(3-trimethoxyproply)proplyenediamine (NDTPD) and thebottom phase a MeOH and HCC1₃ soluble polymer.

EXAMPLE IV-B

The above reaction was repeated with 481.2 gm (2.42 mol) of TMSPC, 740.0gm (7.26 mol) of N,N-dimethylpropylenediamine, and 140 gm MeOH. Thereaction was refluxed for 3 hours and cooled to room temperature. Afterremoval of solvent, by rotary evaporation, NDTPD was obtained.

EXAMPLE V E. Synthesis of Diamine 15.N-3-(trimethoxysilyl)propyl-N-2-(methoxycarbonyl)ethyl-dimethylpropylenediamine-1,3

To a 500 ml round bottom flask was charged a solution of 52.8 gm (0.2mol) of N,N-dimethyl-N'-{3-(trimethoxysilyl)propyl}propylenediamine-1,3and 52.0 gm (0.6 mol) of methyl acrylate and ca. 250 ppm w/w2,6-dihydroxy-4-methylphenol (BHT). The solution was heated to refluxunder air (Ca₂ SO₄ drying tube) for 4.5 hours and analyzed by GC whichshowed that the starting amine had been consumed and a product hadformed. The crude mixture was stripped of volatile components by rotaryevaporation at 40° C./5 mm Hg leaving 68.7 gm of diamine 15.

EXAMPLE VI-A F. Synthesis of Quaternary Salts of Diamine 15

A 250 ml round bottom flask was fitted with a heating mantle, a magneticstirrer, a thermometer, and a reflux condenser with a drying tube. Tothis was charged the reaction solution which was heated to reflux. Fromthe reaction mixture was removed the volatile components by rotaryevaporation at 60° C./4-8 mm Hg. The mixture was washed with solvent,and isolated as a viscous fluid.

EXAMPLE VI-B 1. Quaternization by Methyl Chloroacetate-Synthesis of Quat4

A solution of 10.5 gm (0.03 mol) of diamine 15, 3.26 gm (0.03 mol) ofmethyl chloroacetate, and 20.0 gm of MeOH were charged to the flask.After refluxing for 3 hours, GC showed that the starting material hadbeen consumed. A total of 13.5 gm (98% crude yield) of Quat 4 wasobtained.

EXAMPLE VI-C 2. Quaternization by Benzyl Chloride-Synthesis of Quat 5

A solution of 10.5 gm (0.03 mol) of diamine 15, 4.0 gm (0.03 mol) ofbenzyl chloride, and 15 gm of MeOH were charged to the flask and heatedto reflux. After 1.5 hours, GC showed 5-10% benzyl present along withamine. The reaction was allowed to reflux overnight (ca. 15 hr). GCshowed the benzyl chloride consumed and some amine still present. Benzylmethyl ether was formed as a by-product of the reaction. Excess amineand other residue was removed by vigorous washing of the crude productin ether. After rotary evaporation, 10 gm (70% crude yield) of Quat 5was obtained.

EXAMPLE VI-D 3. Quaternization by Two Equivalents of BenzylChloride-Synthesis of Quat 6

A solution of 10.5 gm (0.03 mol) of diamine 15, 10.0 gm (0.10 mol) totalof benzyl chloride, and 40 gm of MeOH were heated at reflux for 92 hourswhich consumed all of the starting amine. Repeated washing with etherfollowed by rotary evaporation afforded Quat 6 as a white crystallinematerial.

EXAMPLE VI-E 4. Quaternization by iso-Propyl 6-Chlorohexanoate-Synthesisof Quat 7

A solution of 10.5 gm (0.03 mol) of diamine 15, 6.2 gm (0.03 mol) ofisopropyl 5-chlorohexanoate, and 10.0 gm of MeOH was charged to theflask and heated to reflux. After 90 hours, 1.0 gm (5 mmol) of isopropyl3-chlorohexanoate was added to the mixture. At least 5% amine waspresent after refluxing 6 hours and the heating was stopped. The crudeproduct was removed of volatiles by rotary evaporation and washed untilall of the residue was removed leaving 15 gm (94%) of Quat 7.

EXAMPLE VI-F 5. Quaternization by Pentyl Chloride-Synthesis of Quat 8

A solution of 10.5 gm (0.03 mol) of diamine 15, 6.4 gm (0.06 mol) ofpentyl chloride, and 5.0 gm of MeOH were charged to the flask and heatedto reflux for 68 hours and concentrated by rotary evaporation. Repeatedwashing followed by rotary evaporation afforded 13.6 gm (99% crudeyield) of Quat 8.

EXAMPLE VII G. Synthesis of3-{1-{(3,3,3-Trifluoro)propyl}methoxymethylsilyl}propyl Acrylate, 17

To 30 gm (0.28 mol) of allyl acrylate containing 0.75 gm of an activatedplatinum metal catalyst, was added(3,3,3-trifluoropropyl)methylchlorosilane. The addition of the silanewas carried out at 70° C. under 2% O₂ /98% N₂ and the temperature didnot exceed 75° C. When the addition was completed and the mixture hadcooled to 44° C., 100 ml of MeOH containing 25 gm (0.25 mol) of Et₃ Nwas added in a dropwise fashion. White salts were formed. The salts werefiltered and the crude product concentrated by rotary evaporation,redissolved in pentane, filtered, and the pentane removed by rotaryevaporation at 50° C./4 mm Hg. The product was isolated by flashbulb-to-bulb distillation at 72° C./0.2-0.5 mm Hg and afforded 20 gm(25% yield) of Acrylate 17. Acrylate 17 was used in Example VIII.

EXAMPLE VIII H. Michael Addition of Diamine 13 to Acrylate 17-Synthesisof Diamine 11

A solution of 19.4 gm (0.07 mol) of acrylate 17 and 18.0 gm (0.07 mol)of diamine 13 were heated to reflux in a 250 ml round bottom flask for17 hours at which time all of the acrylate had been consumed. To thisrefluxing mixture was added 3 gm (0.03 mol) of allyl acrylate whichconsumed the remaining amine after about 2 hours. After concentratingthe crude product by rotary evaporation, the recovery was 36.4 gm (97%).This material was used in the next Example without further purification.

EXAMPLE IX J. Quaternization of Diamine 11

1. Quaternization by iso-Propyl 6-Chlorohexanoate-Synthesis of Quat 9

A solution of 17.6 gm (0.03 mol) of diamine 11, 8.0 gm (0.04 mol) ofiso-propyl 6-Chlorohexanoate, and 10.0 gm of MeOH was refluxed in a 250ml round bottom flask for 140 hours and stripped of volatiles by rotaryevaporation providing 23 gm (97%) of Quat 9.

2. Quaternization by Pentyl Chloride. Synthesis of Quat 10

A solution of 17.6 gm (0.03 mol) of diamine 11, 4.5 gm (0.04 mol) ofpentyl chloride, and 10 gm of MeOH was refluxed in a 250 ml round bottomflask and stripped of volatiles by rotary evaporation providing 20 gm(95%) of Quat 10.

In order to demonstrate the durability and the substantivity of thecompounds of the present invention, it should be noted that the anion ofan aqueous sodium salt of bromphenol blue can be complexed with thecation of a polymerized silane of this invention while it is on asubstrate. The blue colored complex, substantive to a water rinse, isqualitatively indicative of the presence of the cation on the substratethus indicating the extent of antimicrobial agent on a given substrate.A comparison of the intensity of retained blue color to a color standardis used as a check to determine if the treatment has been appliedproperly.

The method consists of preparing a 0.02 to 0.04 weight percent solutionof bromphenol blue in distilled water. This solution is made alkalineusing a few drops of saturated Na₂ CO₃ solution per 100 milliliters ofthe solution. Two to three drops of this solution are placed on thetreated substrate and allowed to stand for two minutes. The substrate isthen rinsed with copious amounts of tap water and the substrate isobserved for a blue stain and it is compared to a color standard.

For a spectrophotometric determination, the following test is used.

The sodium salt of bromphenol blue is depleted from a standard solutionby complexing with the cations on a treated substrate. The change inbromphenol blue concentration is determined spectrophotometrically or bycomparison with color standards whereby the level of substrate treatmentby the cationic silane is determinable.

The method consists of preparing a 0.02 weight percent standard solutionof bromphenol blue in distilled water. It is made alkaline with a fewdrops of saturated Na₂ CO₃ solution per 100 milliliters of bromphenolblue solution. The color of this solution is purple.

The blank solution is adjusted to yield a 10 to 12% transmittancereading when measured in 1 cm cells using a spectrophotometer set at 589nm by the following method.

Fill a container 3/4 full of distilled water and add 2 ml of the 0.02%standard bromphenol blue solution for every 50 ml of distilled water.Add 0.5 ml of a 1% Triton®X-100 surfactant (manufactured by Rohm andHaas, Philadelphia, PA, U.S.A.) aqueous solution for every 50 ml ofwater. Mix, and using the spectrophotometer, determine the maximumabsorbance. Adjust the upper zero to 100% transmittance with distilledwater. Check the percent transmittance of the working bromphenol bluesolution at the maximum absorbance setting. Adjust the blank solution to10 to 12% transmittance with either water or bromphenol blue standardsolution as necessary.

The samples of treated substrate are tested by placing 0.5 gram samplesof the substrate standards in a flask large enough for substantialagitation of the sample and the test solution. Add 50 ml of the workingsolution. Agitate for 20 minutes on a wrist-action shaker. Fill the testcurvette with the test solution. Centrifuge if particulate matter ispresent. Measure the % transmittance at the wavelength set forth above.The transmittance is compared against a standard curve prepared bypreparing several substrate samples of known concentration of thecationic silane. For example, samples containing a known amount ofcationic silane at, for example, 0%, 0.25%, 0.50%, 0.75% and 1% are readspectrophotometrically and a curve is plotted.

The foregoing test was carried out for each compound at levels of 0.1%,0.3%, and 0.5%, based on weight of fiber, and the surface was rayon. Theresults are tabulated in Table I below, and Series No. 1 indicatesoriginal as is treated fabric samples, whereas Series No. 2 indicatesthose same Series No. 1 original samples re-tested but only after havingbeen subjected to a sodium dodecylbenzylsulfonate wash followed by analcohol salt rinse and dried. Control samples of untreated rayon arealso shown.

                  TABLE I                                                         ______________________________________                                                   Percent Transmittance                                              Quat No.     Series No. 1                                                                             Series No. 2                                          ______________________________________                                        Control      11.4       10.8                                                  0.1%         11.2       10.3                                                  0.3%         11.0       10.3                                                  0.5%         11.0       10.2                                                  2                                                                             Control      11.4       10.8                                                  0.1%         11.0       10.5                                                  0.3%         11.5        9.8                                                  0.5%         14.2        9.9                                                  3                                                                             Control      11.4       10.8                                                  0.1%         11.4       10.5                                                  0.3%         18.2       10.9                                                  0.5%         11.9       10.4                                                  4                                                                             Control      11.4       11.2                                                  0.1%         11.1       11.2                                                  0.3%         11.2       11.7                                                  0.5%         11.5       11.0                                                  5                                                                             Control      10.8       11.3                                                  0.1%         13.7       11.0                                                  0.3%         15.5       10.9                                                  0.5%         20.2       11.4                                                  6                                                                             Control      10.8       10.9                                                  0.1%         16.7       11.3                                                  0.3%         22.1       11.0                                                  0.5%         42.9       10.6                                                  7                                                                             Control      10.8       10.9                                                  0.1%         12.5       10.9                                                  0.3%         13.5       11.2                                                  0.5%         15.7       11.1                                                  8                                                                             Control      11.4       10.8                                                  0.1%         11.2       10.3                                                  0.3%         11.8        9.9                                                  0.5%         12.2       10.4                                                  9                                                                             Control      10.8       10.9                                                  0.1%         12.1       11.0                                                  0.3%         13.4       11.4                                                  0.5%         15.0       11.6                                                  10                                                                            Control      10.8       11.3                                                  0.1%         11.9       11.6                                                  0.3%         13.0       11.3                                                  0.5%         15.2       11.5                                                  ______________________________________                                    

In order to demonstrate the antimicrobial activity of the compounds ofthe present invention, the following test was conducted.

The antimicrobial activity of a rayon treated surface was evaluated byshaking a sample weighing 0.75 grams in a 750,000 to 1,500,000 countKlebsiella pneumoniae suspension for a one hour contact time. Thesuspension was serially diluted, both before and after contact, andcultured. The number of viable organisms in the suspensions wasdetermined. The percent reduction based on the original count wasdetermined. The method was intended for those surfaces having areduction capability of 75 to 100% for the specified contact time. Theresults are reported as the percent reduction.

Media used in this test were nutrient broth, catalog No. 0003-01-6 andtryptone glucose extract agar, catalog No. 0002-01-7 both available fromDifco Laboratories, Detroit, Mich., U.S.A. The microorganism used wasKlebsiella pneumoniae American Type Culture Collection; Rockville, Md.U.S.A., catalog No. 4352.

The procedure used for determining the zero contact time counts wascarried out by utilizing two sterile 250 ml. screw-cap Erlenmeyer flasksfor each sample. To each flask was added 70 ml of sterile buffersolution. To each flask was added, aseptically, 5 ml of the organisminoculum. The flasks were capped and placed on a wrist action shaker.They were shaken at maximum speed for 1 minute. Each flask wasconsidered to be at zero contact time and was immediately subsampled bytransferring 1 ml of each solution to a separate test tube containing 9ml of sterile buffer. The tubes were agitated with a vortex mixer andthen 1 ml of each solution was transferred to a second test tubecontaining 9 ml of sterile buffer. Then, after agitation of the tubes, 1ml of each tube was transferred to a separate sterile petri dish.Duplicates were also prepared. Sixteen ml of molten (42° C.) tryptoneglucose extract agar was added to each dish. The dishes were eachrotated ten times clockwise and ten times counterclockwise. The disheswere then incubated at 37° C. for 24 to 36 hours. The colonies werecounted considering only those between 30 and 300 count as significant.Duplicate samples were averaged. The procedure used for determining thebacterial count after 1 hour was essentially the same as that used todetermine the count at the zero contact time. The only difference wasthat pour plating was performed at the 10⁰ and 10⁻¹ dilutions as well asat the 10⁻² dilution. "Percent reduction" was calculated by the formula##EQU1## where A is the count per milliliter for the flask containingthe treated substrate; B is zero contact time count per milliliter forthe flask used to determine "A" before the addition of the treatedsubstrate and C is zero contact time count per milliliter for theuntreated control substrate.

The foregoing test was carried out for each compound at levels of 0.1%,0.3%, and 0.5%, based on weight of fiber. As noted above, the surfacewas rayon. The results are tabulated in Table II below, and Series No. 1indicates original as is treated fabric samples, whereas Series No. 2indicates those same Series No. 1 original samples re-tested but onlyafter having been subjected to the foregoing durability treatment.Control samples of untreated rayon are also shown.

                  TABLE II                                                        ______________________________________                                        Percent Reduction                                                             Quat No.     Series No. 1                                                                             Series No. 2                                          ______________________________________                                        Control      48.3       60.9                                                  0.1%         73.5       40.9                                                  0.3%         89.9       53.0                                                  0.5%         94.4       71.0                                                  2                                                                             Control      47.7       60.9                                                  0.1%         80.1       62.0                                                  0.3%         94.2       56.4                                                  0.5%         98.8       58.8                                                  3                                                                             Control      50.5       60.9                                                  0.1%         91.0       53.7                                                  0.3%         99.6       61.3                                                  0.5%         99.9       75.4                                                  4                                                                             Control      --         55.4                                                  0.1%         73.5       53.5                                                  0.3%         79.4       37.6                                                  0.5%         92.3       58.4                                                  5                                                                             Control      46.4       64.9                                                  0.1%         96.5       75.6                                                  0.3%         99.7       67.8                                                  0.5%         100.0      80.5                                                  6                                                                             Control      53.0       47.5                                                  0.1%         99.8       56.7                                                  0.3%         100.0      71.4                                                  0.5%         100.0      74.1                                                  7                                                                             Control      42.7       47.5                                                  0.1%         99.7       70.1                                                  0.3%         100.0      74.0                                                  0.5%         100.0      95.1                                                  8                                                                             Control      49.2       60.9                                                  0.1%         72.9       62.7                                                  0.3%         99.2       63.3                                                  0.5%         99.9       78.5                                                  9                                                                             Control      45.6       47.5                                                  0.1%         99.8       70.5                                                  0.3%         100.0      82.6                                                  0.5%         100.0      93.7                                                  10                                                                            Control      50.6       64.9                                                  0.1%         97.9       59.4                                                  0.3%         99.6       87.0                                                  0.5%         100.0      90.8                                                  ______________________________________                                    

The compounds of the present invention are useful in applications wherethe reduction in number or elimination of microorganisms on a surface orother material is desired.

It will be apparent from the foregoing that many other variations andmodifications may be made in the structures, compounds, compositions,and methods described herein without departing substantially from theessential features and concepts of the present invention. Accordingly,it should be clearly understood that the forms of the inventiondescribed herein are exemplary only and are not intended as limitationson the scope of the present invention.

That which is claimed is:
 1. A compound of the formula ##STR12## whereinMe is methyl.